Circulation fluid screen



Dec. 30,1941; "E. c. SMiTH CIRCULATION FLUID SCREEN -2 Sheets-Sheet 1 Filed Dc. 30, 1939 INVENTOR. ERNEST (3- SM/ TH BY I M A TTORN? E. c. SMITH 2,268,065

CIRCULATION FLUID SCREEN Filed Dec. 30, 1939 2 Sheets-Sheet 2 IQNVENTOR. I, ER/VEST (f SMITfI ArToR/vEX move any thin mud that may adhere to the under Patented Dec. 30, 1941 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to a screen particularly designed for use in connection with deep well drilling apparatus for the purpose of separating sand, shale and the like from. the circulation fluid or mud that is pumped downwardly into the well for the purpose of facilitating drilling and for carrying to the surface of the ground the cuttings that are removed from the formation by the drill.

It is to be understood that in the drilling of deep wells, for instance, oil and gas wells, it is the general practice to use a drilling fluid that is pumped downwardly into the well for the purpose of cooling and lubricating the bit and carrying away the cuttings.

In order that this fluid may be reused, it is highly essential that all foreign matter such as sand, shale and the like, which would otherwise materially affect and cause rapid wear of the drill, valves and. other parts of the apparatus through which the circulation fluid passes, be removed from the fluid and to accomplish this result, I propose to provide an endless belt-like screen composed of wire, to mount said endless screen upon a pair of rollers and to drive said rollers. by means actuated by the force of the circulation fluid that is circulated through the well by means of a conventional pump.

It is one of the principal objects of my invention to combine with the endless screen a pair of pans, one of which carries off the fluid from which sand, shale and other foreign matter has been removed, and which fluid returns to the pump to be forced downwardly into the well hole and the other pan being arranged to receive and direct the passage of sand, shale and the like, to a duct that leads to a refuse sump or the like.

A further object of my invention is to provide a scraper that is arranged to engage and relit side of the over-running portion of the endless screen and to provide means whereby a plurality of jets of water under pressure are delivered onto and through the under-running portion of the screen so as to remove accumulations such as mud, shale and the like, that may tend to adhere to the under surface of said under-running portion of the screen.

With the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts that will be hereinafter more fully described and claimed and illustrated in the accompanying drawings in which:

Fig. 1 is a top plan view of a circulation fluid Fig. 2 is a side elevational view of the lower portion of the screen.

Fig. 3 is a vertical longitudinal section taken on theline 3-3 of Fig. 1.

Fig. 4 is a partial cross section taken on the line 4-4 of Fig. 3.

Fig. 5 is a cross section taken on the line 5-5 of Fig. 3.

Fig. 6 is a perspective view of the scraper utilized in my improved circulation fluid screen.

Referring by numerals to the accompanying drawings which illustrate a preferred embodiment of my invention, Ill-40 designate the side rails which together with end rails ll form a rectangular base for the support of the screen and the operating parts thereof. Surmounting this base isa skeleton frame, preferably come posed of flanged metal rails including side mem hers 62 that are disposed a short distance above and parallel with the side rails ll] and suitably connected to the rails I2 are cross rails l3. This upper rail is supported from the base structure by means of vertically disposed posts I4.

Suitably secured to one of the end rails l3 of the upper frame and to the adjacent cross rail is a tank l5, preferably formed of sheet metal, and connected to the lower portion of one of the end walls thereof is a pipe l6 that delivers the circulation fluid from thetop of the well hole to tank l5.

Portions H of the side walls of the tank l5 adjacent the end to which the pipe I6 is connected are inset so as to provide a narrow chamber l8, into the lower portion of which pipe IE discharges and the forward portions I9 of said side walls diverge toward the end wall opposite the end wall to which pipe 4'' is connected.

Journalled in suitable bearings 29 on one side of the frame that supports tank 15 and on one of the side rails I2 is a shaft 21 that extends through bearings 22 on the portions ll of the side wallsof the tank and secured to the central .portion of this shaft within the narrow portion l8 of the tank is a conventional paddle wheel 23, the outer portions of the blades of which traverse a circular path, the lower portion of which is directly in line with the pipe I6.

J ournalled in bearings 24 that are mounted on the side rails Iii of the base frame are rollers 25, each provided with an elastic or flexible surface, such as rubber, leather, felt or the like. One of these rollers is positioned beneath tank 15 a short distance inwardly from the end wall opposite the end wall to which pipe I6 is connected and formed in the bottom of tank l above this one of the rollers is an opening 26.

Arranged for operation upon the rollers 25 is an endless or belt-like screen 21, preferably composed of wire screen of small mesh,and suitably supported between the rollers and between the over and under-running portions of the endless screen is a pan 21a, preferably composed of sheet metal, one end of which is closed by an end wall 28 and the opposite end of this pan projects beyond the side of the apparatus and discharges into a chute or duct 29 that leads to a tank or sump (not shown) from which the pump draws fluid to be circulated through the well.

One end of shaft 2| projects beyond the side of the apparatus and mounted on the end of said projecting portion is a beveled pinion 30. Journalled in bearings located on the side of the .frame of the apparatus is a shaft 3| and secured on the upper end thereof is a beveled pinion 32 that meshes with pinion 35. The lower end of shaft 3| [carries a beveled pinion 33 that meshes With a beveled pinion 34, the latter being carried on the end of the sha'ft'that carries that one of the rollers 25 that is positioned beneath tank l5.

Pan 21a is provided with side walls 35 that are located immediately adjacent the peripheries of the rollers 25 and secured to the end wall of the pan adjacent the roller 25 opposite the roller that is driven by shaft 3| and its connections is a transversely disposed channel 38 in which is carried a series of separately formed blocks 31 of rubber or the like, the upper ends of which are adaptedto engage the under surface of the over-running portion of the endless screen.

If desired, a single long strip of rubber may be used in place of the rubber blocks 31 although I prefer to use the blocks inasmuch as such provision enables any one of said blocks to be readily removed and replaced in the event that it becomes worn or broken While in service.

Arranged just below the end wall that carries the scraper comprising the channel 36 and blocks or strip of rubber is a transversely disposed tube 38 in which is formed a row or IOWs of apertures disposed so that they will direct jets of water downwardly onto and through the under-running portion of the screen just after the same leaves the roller 25 adjacent the side wall 35 that carries the scraper. Thus all sand, shale and the like that might otherwise adhere to the outer surface of the endless screen will be washed therefrom by the jets of water issuing from the apertures in tube 38.

Suitably supported within the base frame comprising the rails l0 and II is a shallow pan 39 that is slightly longer and wider than the structure comprising the screen 21 and rollers 25 and the bottom of this pan declines slightly toward the end that is positioned beneath the roller that is located adjacent the scraper and the perforated tube 38.

Formed in the lowermost end of this pan 39 is an outlet opening 4!) and arranged transversely below the base frame and below the discharge opening 40 is a trough 4| that leads to a sump or other depression that receives the sand, shale and other waste matter that is screened from the circulation fluid.

Perforated tube 38 is connected on one side of the apparatus to a waste supply pipe 42 that leads to a suitable source of water supply under pressure and located in this pipe is a manually operable valve 43 that controls the flow of water to and through the perforated pipe. Located in pipe 42 adjacent and in front of valve 43 is a short branch pipe 44 in which is located a valve 45, thus providing means for supplying water to a hose or the like that may be used in flushing the pans 21a and 39 and cleaning the other parts of the apparatus.

In the use of my improved screen, the circulation fluid that is drawn from the well by the circulation pump is delivered to pipe l6 and such fluid containing sand, shale and cuttings from the formation in which the drill is Working are delivered under pressure into the lower portion of tank l5 and such action imparts rotary motion to the paddle wheel 23. As the paddle wheel is thus rotated, motion will be transmitted through pinions 30 and 32 to shaft 3| and through pinions 33 and 34 to roller 25 that is located beneath the tank l5. Thus as this roller 25 is rotated, the endless screen will be caused to travel around the two rollers with the over-running portion of said screen traveling away from the tank l5.

The fluid after engaging the paddles of Wheel 23 will discharge through opening 26 onto the over-running portion of the endless screen and as said over-running portion travels to the roller 25 adjacent the scraper and perforated tube 38, the water will discharge through said screen and pass into pan 21a and, the sand, shale and other Waste materials will discharge from the forward end of the screen and pass downwardly through opening 40 into trough M.

The circulation fluid that discharges into pan 27a will flow to the side thereof that is connected to trough 29 and by means of the latter, this fluid will pass back to the clean fluid sump or container from which the pump draws its supply. The sand, shale and other waste material passes through trough 4| and discharges into a sump or other depression.

In some localities or fields where oil wells are drilled, the waste from the circulation fluid contain-s certain chemicals having more or less commercial values and where such condition exists, the waste material delivered into the sump or depression through trough 4| may be treated to recover such chemicals.

Any mud that may pass through the over-running portion of the screen and adhere to the under side thereof will be removed and delivered into the pan 21a by the scraper comprising channel 36 and rubber blocks 31 and such mud unites with the screened fluid that flows from pan 21a to the pump.

Any sand or small particles of shale or the like that adhere to the outer surface of the endless screen will be washed therefrom by the jets of water that issue from tube 38 and these washings pass into pan 39 and mix with the waste materials therein.

Thus it will be seen that I have provided a circulation fluid screen that is relatively simple in construction, inexpensive of manufacture and very effective in performing the functions for which it is intended.

It will be understood that minor changes in the size, form and construction of the various parts of my improved circulation fluid screen, may be made and substituted for those herein shovm and described, without departing from the spirit of my invention, the scope of which is set forth in the appended claims. 7

1 claim as my invention;

1. In a circulation fluid screen, a frame, a pair of rollers journalled for rotation in said frame, an endless screen mounted for operation on said rollers, a pan arranged between said rollers beneath the over-running portion of said screen, said pan having an outlet on one side thereof, a second pan arranged beneath said rollers and screen, said second mentioned pan having an outlet near one end and a scraper arranged transversely beneath the over-running portion of said endless screen adjacent its discharge end, which scraper comprises a row of separately formed blocks of flexible material that have rubbing contact with the, under surface of said screen.

2. A circulation fluid screen as set forth in claim 1,, with a tank arranged above one end of said endless screen, said tank being provided in its lower portion with an outlet, a paddle wheel arranged for operation withinsaid tank, means for delivering a jet of fluid into the lower portion of said tankagainst the lower portions of the paddles of said paddle wheel and means for driving one of said rollers from said paddle wheel.

3. In a circulation fluid screen, a frame, a pair of rollers journalled for rotation in said frame,

an endless screen mounted for operation on said rollers, a pan arranged between said rollers beneath the over-running portion of said screen, said pan having an outlet on one side thereof, a second pan arranged beneath said rollers and screen, said second pan having an outlet near one end, a tank mounted on the frame above one end of said endless screen, said tank being provided in its lower portion with an outlet for discharging fluid directly onto the over-running portion of the screen, a paddle wheel arranged for operation within said tank, means for directing a jet of fluid into said tank against the paddles of said paddle wheel, driving connections between said paddle wheel and one of the screen carrying rollers, a scraper transversely disposed beneath the over-running portion of the endless screen adjacent its discharge end, which scraper comprises a row of separately formed blocks of flexible material and means for delivering jets of water downwardly through the under-running portion of said screen.

4. In a circulation fluid screen, a pair of rollers journalled for rotation, an endless screen mounted for operation on said rollers, a pan arranged between said rollers beneath the over-running portion of said screen and a scraper arranged beneath the over-running portion of the screen adjacent its discharge end, which scraper comprises a row of separately formed blocks of flexible material.

ERNEST c. SMITH. 

